You searched for: “bioterrorists
bioterrorist (s) (noun), bioterrorists (pl)
A terrorist who uses biological weapons: "Not only water supplies are susceptible to such deliberate contamination; so, too, is much of the air we breathe."

"Skyscrapers, tunnels, subways, and their requisite heating and air-conditioning systems provide targets and also ways of attack for would-be bioterrorists."